I don't even use my OAV applicator below my screened bottom board - it's too hard to get adequate vapor thru the hive. I am not familiar with the beetle buster boards. I got tired of burned bees and have experimented with 2 systems of getting OAV above the SBB, finally built a dispenser of a pvc primer can with my OAV wand inside it, and I really like that. Small hole, good coverage, good mite drop. And I can treat from the back side of the hive, less bee traffic